Dynamic self-calibration of an accelerometer system

Abstract

One embodiment includes a method for dynamic self-calibration of an accelerometer system. The method includes forcing a proof-mass associated with a sensor of the accelerometer system in a first direction to a first predetermined position and obtaining a first measurement associated with the sensor in the first predetermined position via at least one force/detection element of the sensor. The method also includes forcing the proof-mass to a second predetermined position and obtaining a second measurement associated with the sensor in the second predetermined position via the at least one force/detection element of the sensor. The method further includes calibrating the accelerometer system based on the first and second measurements.

What is claimed is: 
     
       1. A method for dynamic self-calibration of an accelerometer system, the method comprising:
 forcing a first proof-mass associated with a sensor of the accelerometer system in a first direction from an electrostatic null position to a first predetermined position in response to a first perturbation of the electrical null; 
 obtaining a first measurement associated with a second proof-mass of the sensor with the first proof-mass in the first predetermined position via at least one first force/detection element of the sensor, the second proof-mass being coupled to the first proof-mass via a set of flexures; 
 forcing the first proof-mass in a second direction opposite the first direction from the electrostatic null position to a second predetermined position that is symmetrical with respect to the first predetermined position in response to a second perturbation of the electrical null, the first and second perturbations being approximately equal and opposite; 
 obtaining a second measurement associated with the second proof-mass of the sensor with the first proof-mass in the second predetermined position via at least one second force/detection element of the sensor; and 
 calibrating the accelerometer system based on the first and second measurements. 
 
     
     
       2. The method of  claim 1 , wherein obtaining the first and second measurements comprises:
 measuring a first net force applied to the second proof-mass via the at least one first force/detection element; and 
 measuring a second net force applied to the second proof-mass via the at least one second force/detection element. 
 
     
     
       3. The method of  claim 1 , wherein obtaining the first and second measurements comprises measuring a first net force applied to the second proof-mass via the at least one first force/detection element and measuring a second net force applied to the second proof-mass via the at least one second force/detection element, the method further comprising:
 calculating a difference between the first measurement comprised of a first capacitance and the second measurement comprised of a second capacitance; and 
 adjusting the electrostatic null position based on the difference between the first capacitance and the second capacitance. 
 
     
     
       4. The method of  claim 3 , wherein adjusting the electrostatic null position comprises adjusting a relative signal between the first at least one force/detection element and the second at least one force/detection element at the electrostatic null position.